Combined ahead and astern turbine.



H. W. RIDSDALE '& S. S. COOK.

COMBINED AHEAD AND ASTERN TURBINE.

APPLICATION TILED JULY 28, 1911.

1 ,022,2 1 5, Paten ted Apr. 2, 1912.

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UNITED STATES PATENT @FFICE.

HERBERT WHEATLEY RIDSDALE, OF LONDON, AND STANLEY SMITH COOK, OF WALLS- END, ENGLAND, ASSIGNORS TO CHARLES ALGERNON PARSONS, OF NEWCASTLE- UPON-TYNE, ENGLAND.

COMBINED AHEAD AND ASTERN TURBINE.

Specification of Letters Patent.

Patented Apr. 2, 1912.

T 0 all whom it may concern:

Be it known that we, Iinnmnrr lVItn vrmir RiosoALn, a subject of the King of Great Britain and Ireland, and residing at Capel House, 62 New Broad street, London, England, and STANLEY Siirrn Coon, a subject of the King of Great Britain and Ireland, and residing at Turbinia \Vorks, \Vallsendon-Tyne, in the county of Northumberland, England, have invented certain new and useful Improvements in and Itelating to Combined Ahead and Astern Turbines, of which the following is a specification.

This invention relates to improvements in combined ahead and astern turbines oi the type described in the Serial No. (308583, February 14:, 1911, in which a single dummy or balancing piston is adapted to enable the required balancing thrust to be obtained when either the ahead or the astern turbine is in action, such balancing piston being arranged at the admission point to one turbine and connected to the admission space of the other turbine through the interior of a hollow rotor or by suitableexternal pipe means.

Considerable economy in steam consumption is obtained, as is already well known, by admitting low pressure steam exhausted from auxiliary enginesto a low pressure stage of a turbine. In combined ahead and astern turbines, however, such exhaust steam is usually admitted to a low pressure stage of the ahead turbine and it has been necessary to provide special pipe connections and. valves therein by which the supply of auxiliary steam can be by-passed when the astern turbine is in action.

The object of the present invention is to overcome such a disadvantage and to provide an arrangement of turbines according to the above patentin which the existing pipe means can be used for the admission of such exhaust steam.

The invention consists for this purpose in a combined ahead and astern turbine of the above type in which a branch connection from the external pipe means controlled by a three-way valve is adapted to place one side of the single balancing or dummy piston in communication with a lower pressure stage of either the astern or the ahead turbine, low pressure steam from the auxiliary engine being admitted to said external pipe means at a point therein between the threeway valve and dummy piston whereby said steam is supplied to either the ahead or astern turbine.

The invention also consists in the improved combined ahead and astern turbine hereinafter described.

In the form of turbine illustrating by way of example one method of carrying the present invention into ellect, the ahead turbine comprises an impulse wheel, (I, followed by reaction sections, Z), and (1, preferably separated by a stepped part, (Z, on the combined turbine rotor, while the astern turbine has an impulse wheel, 0, followed by a reaction section, f. Steam is admitted to the turbines from a supply pipe, g, by a threeway valve, ii, to pipes, z and 7', leading respectively to the inlet nozzles of the ahead and ot the astern turbine, both of which turbines exhaust into a common cduction pipe, in. At the ahead turbine end of the rotor, there is a single dummy or balancing piston, Z, placed in front of the impulse wheel, a, and separated from the chamber containing the latter, by a packing, we, placed between the piston and the turbine casing. The side of the piston. Z, remote from the astern turbine is placed in communication with a low pressure stage of the astern turbine, for example with the chamber containing the impulse wheel, (1, by means of external pipe connections, a and 0, while communication between the dummy piston, Z, and a lower n'cssure stage of the ahead turbine is established through a pipe connection, 7), branching from the pipe connection, n, and leading to the chamber containing the annular surface, (Z, between the two portions, 7) and c, of the ahead reaction part. The adjustment necessary for establishing communication between the space behind the dummy piston, Z, and the stage of the astern turbine or of the ahead turbine, is effected by means of a three-way valve, q, adapted to control the passage oi steam from the pipe connection, a, to the connection, 0 or 7?, respectively, the adjustment of this valve being preferably effected sinniltaneously with the opening of the valve, 71, by which steam is admitted to either turbine part. For this purpose the valve h, as shown, is of the ordinary slide valve type and has a sliding part, 1*, mounted upon a rod, 8, which can be moved by rotating a hand wheel, t, which has a screw threaded connection therewith. The movement of the sliding piece, '2", etfects the uncovering of one of the ports a or 41, whereby steam is admitted either into the pipe connection, or j. The three-way valve 9, is also of the ordinary slide valve type, having a sliding piece, Qt, mounted upon a rod, x, connected to the valve rod, .9, by a pivoted member, y, so that on the valve part 1 being moved, in one direction, the valve part, 11;, moves in the opposite direction to uncover one of the ports, .2, or Z, by which steam is admitted from the pipe, n, to the pipe, 7), or to the pipe, 0, respectively.

YVhen the ahead turbine is in action, the valves are arranged as shown in the figure, from which it will be seen that steam from the supply pipe, g, will pass through the valve port, a, into the pipe connection, 2', leading to the ahead turbine inlet nozzles, while the piston, Z, will be subjected to the pressure of the steam in a lower stage of the ahead turbine on account of this stage being now in communication through the pipe connection, n, port, 2 and pipe connection, 79.

Obviously when the slide valve, 1, is moved to the left and the slide valve, 7.0, to the right, steam will be admitted from the supply pipe, g, through the port, 4), to the pipe, j, and astern turbine, while at the same time the dummy piston, Z, will be put in communication with a lower pressure stage of the astern turbine by means of the pipe connections, n and 0, which are now in communication through the open port, Z.

According to the present invention, exhaust steam from an auxiliary engine is admitted to either turbine part by utilizing the already existing pipe connections, this being effected by leading such steam into the system by means of a branch pipe connection, 2, preferably from the pipe, 17.. Such an arrangement insures that it will be unnecessary in all cases to provide special means for regulating such exhaust steam, as in consequence of the adjustment of the three-way valve, being effected simultaneously with that of the main valve, it, such steam will always be admitted to an active turbine stage. Further, any steam leaking past the packing, 172-, will be conducted back to and used in the reaction section, 0, of the ahead turbine, in which the low pressure steam admitted by the pipe connections, 9., and p, from the auxiliary engines, is "further utilized.

During the operation of the astern tur bine, any steam leakin through the packing, m, passes through the reaction blading, I), and 0. On account of the very slight drop of pressure, the quantity of leakage steam however is so small in proportion to the available cross sectional areas of the ahead turbine, that the leakage steam can not have any harmful influence.

Instead of the dummy piston being placed at the ahead turbine end, it can equally well be arranged at the astern turbine end, the pipe connections in such a case being correspondingly reversed. The arrangement shown in the accompanying drawings, however, is lnuch more suitable since the ditlerence of pressure across the packing gland where the shaft passes through the turbine casing, is less than when the dummy is placed at the astern turbine end of the rotor.

Though turbines having impulse sections followed by reaction sections have been illustrated, it will be seen that turbines having reaction sections only may be used in the turbine according to the present invention, and that many other modifications may be made in the details of construction without in any way departing from the spirit of the invention.

Having now described our invention what we claim as new and desire to secure by Letters Patent is 1. In a turbine having ahead and astern turbine parts, a single balancing piston, connecting means by which one side of said piston is subjected to the pressure in a stage of either turbine part when in action, and means for supplying said stage with additional working fluid which passes thereto through the existing connecting means.

2. In a turbine having ahead and astern turbine parts, a single balancing piston, external pipe means placing one side of the piston in communication with a stage of the turbine part in action, and means for supplying said stage with additional working fluid which passes thereto through the existing pipe means.

3. In a turbine having ahead and astern turbine parts, a single balancing piston, external pipe means adapted to place auto matically one side of said piston in communication with a stage of the turbine part in action, and means for supplying said stage with additional working iuid which passes thereto through the existing pipe means.

4. In a turbine having ahead and astern turbine parts, a single balancing piston, external pipe means capable of placing a stage of either turbine part in communication with one side of the balancing piston, valve controlling means situated in the pipe means and adapted to place said piston in communication with the turbine part in action, and means whereby a stage 01": the active turbi'ne part is supplied with additional working fluid which passes thereto through the existing pipe means.

5. In a turbine having ahead and astern turbine parts, a single balancing piston, external pipe means adapted to place a stage of either turbine part in communication with one side of the balancing piston, valve controlling means situated in the pipe means and adapted to place the piston in communication with the turbine part in action, and means placed between said valve means and the piston, whereby additional working fluid can be passed through the existing pipe means and supplied to the turbine part in action.

6. In a turbine having ahead and astern turbine parts, a single balancing piston, an external pipe connection placing one side of the balancing piston in communication with a Stage of one turbine part, a branch pipe connection from said external pipe connection to a stage of the other turbine part, a three-way valve between said pipe connection and the branch pipe therefrom, and means admitting additional working fluid to said pipe connection between the valve and piston whereby said fluid is admitted to either turbine part and the turbine is balanced during either ahead or astern movement.

7. In a turbine having ahead and astern turbine parts, a single balancing piston, an external pipe connection placing one side of the balancing piston in communication with a stage of one turbine part, a branch pipe connection from said external pipe connection to a stage of the other turbine part, a threeavay valve between said pipe connection and the branch pipe therefrom, and means admit-ting additional working fluid to said pipe connection between the valve and piston, and means adjusting the threeway valve simultaneously with the admission of fluid to one of the turbine parts in order to subject the piston to the pressure of the fluid in the active turbine part whereby said additional working fluid is admitted to either turbine part and the turbine is balanced during either ahead or astern movement.

8. In a turbine having ahead and astern turbine parts comprising one or more impulse stages followed by a reaction section, a balancing piston placed at the inlet end of the ahead turbine part, an external pipe connection placing one side of the piston in communication with an impulse stage of the astern turbine, a branch pipe connection leading from the external pipe connection to a stage of the ahead turbine reaction section, a three-way valve placed at the junction of the branch pipe connection with the external pipe connection thus allowing said piston to be subjected to the fluid pressure in either turbine part, and means admitting additional Working fluid to the external pipe connection between the valve and the piston whereby this lluid is supplied to either urbine part by means of the existing pipe connections.

9. In a turbine having ahead and astern turbine parts comprising one or more impulse stages t'ollowed by a reaction section, a balancing piston placed at the inlet end of the ahead turbine part, an external pipe connection placing one side of the piston in communication with an impulse stage of the astern turbine, a branch pipe connection leading from the external pipe connection to a stage of the ahead turbine reaction section, a three-way valve placed at the junction of the branch pipe connection with the external pipe cormcction, means acting upon said valve simultaneously with the admission of fluid, to one of the turbine parts to place the piston in communication with the turbine part in operation, thus allowing said piston to be subjected to the fluid pressure in either turbine part, and means admitting additional working fluid to the external pipe connection between the valve and the piston whmrcby this fluid is supplied to either turbine part by means of the existing pipe connections.

10. In a turbine having ahead and astern turbine parts comprising one or more impulse stages followed by a reaction section,

a balancing piston placed at the inlet end of the ahead turbine part, an external pipe connection placing one side of the piston in communication with an impulse stage of the astern turbine, a branch pipe connection leading from the external pipe connection to a stage of the ahead turbine reaction section, a three-way valve placed at the j auction, of the branch pipe connection with the external pipe connection, positively actuated means adjusting the threeay valve to subject the balancing piston to the pressure of the fluid in a stage of the active turbine part thereby balancing the propeller thrust due to the latter, and means admitting additional working fluid to the external pipe connection between the valve and the piston whereby the additional working lluid is supplied to either turbine part by means of the existing pipe connections.

In testimony whereof, we. atlix our signatures in presence of two witnesses.

HERBERT WHEA'ILEY RIDSDALE. STANLEY SMITH COOK. \Vitnesses A. E. TAYLOR, S. NICIIOLL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D C. 

